Gun synchronization



Aug. 2, 1949. v. F. ZAHODIAKIN 2,477,919

GUN SYNCHRONIZATION Filed April 14, 1945 e Sheets-Sheet 1 INVENTYOR.

ATTORNEYS.

Aug. 2, 1949. v. F. ZAHODIAKIN 2,477,919

GUN SYNCHRQNIZATION 6 Sheets-Sheet 2 Filed April 14, 1945 A INVENTOR. Q

q ATTORNEKi Aug. 2, 1949. v. F. ZAHODIAKIN GUN SYNCHRONIZATION 6 Sheets-Sheet 3 Filed April 14, 1945 IN V EN TOR.

ATTORNEYS.

I v Aug. 2, 1949. v. F. ZAHODlAKlN GUN SYNCHRONIZATION 6 Sheets-Sheet 4 Filed April 14, 1945 ATTORNEIS" INVENTOR la /I 72 I rill/,4

Aug, 2, 1949. v'. F. ZAHODIAKIN GUN- SYNCHRONIZATION l A I 6 Sheets-Sheet 5 INVENT'OR- Filed April 14, 1945 Aug. 2, 1949. v. F. ZAHODlAKlN GUN SYNCHRONIZATION 6 Sheets-Sheet 6 Filed April 14, 1945 INVENTO R.

ATTORNEYS.

Patented Aug. 2, 1-949 UNHE D ET I TES 2,477,919 'GUN SYNCHRONIZATION Victor F. Zahodiakin, Short Hills, N. I. .Ap xlicationApril 14, 1945, Serial No. 588,273

s'Claims. 1

This invention relates to the control of the firing of machine guns.

The principal purpose of this invention has been to provide a mechanism for causing machine guns to fire simultaneously and in synchronism, in order that the recoil of one gun will not alter or affect the aim of another. The invention is particularly useful for controlling operation of machine guns mounted in multiple upon a com-- mon gun base, such as :a rotatable turret in an air-plane. If the guns of such an installation are fired alternately or heterogeneously a reciprocataction is imposed upon the turret which, unless it is exceedingly strong and rugged, may cause the turret to move and thereby impair the accuracy of the aim.

The present invention contemplates a mechanism through which the operations of the .guns are intercontrolled such that no gun can be discharged before another. Otherwise expressed, each gun, during-operation, conditions itself automatically to be discharged, subject to release or discharge by the gun which is last to be conditioned for release. The invention also contemplates an emergency control system whereby each gun may be operated independently of another should either become jammed or inoperative. .All or" the mechanism is adapted tobe associated with conventional machine gun equipment, as in the nature of an attachment therefor, or it may "be incorporated into the guns as integral parts thereof, as the case may be.

Briefly, this synchronizing equipment comprises a primary controller -for each gun which is responsive to its operation; each gun also has a firing controller which, when actuated, causes discharge; and each gun has a linkage interconhating the primary controller thereof with the firing controller. These linkages are cross-connected or associated with one another through intercontrol device which provides lost motion of such nature as to prevent transmission of movement from the primary controller to the firmg controller of one gun but not both. Thus the gun first ready to be fired utilizes this available lost motion and, in utilizing it, renders the linkages of all guns effective for transmitting motion, whereby the primary controller of the gun which is last to be ready to fire sets off both.

In the preferred embodiment of the invention, for convenience in mounting and simplicity in structure the linkage mechanism includes flexible cables interconnecting the primary controllers respectively with the intercontrol, and the intercontrol with the respective firing controllers.

While each gun is being loaded, that is, while a cartridge automatically is being inserted into the chamber, the cable system of that gun or at least a part thereof is slack. Next, when the gun is ready to be fi-redthe slack automatically is taken up and the cable system for the gun is rendered efiective for transmitting motion, :but no motion actually is transmitted from the primary controller to the firing controller of that gun by virtue of "the lost motion which is available at the :intercontroller. Therefore, the firing of the gun is delayed until the other gun reaches that stage of its operation where it too is ready 'to be fired, whereupon the automatic take-up of its slack places a tug upon the entire system and discharges'both guns.

As an emergency device the intercontrol-ler is provided with means for renderin its 10st motion apparatus ineffective and in this manner the cross control between the guns is neutralized and each is capable of heing operated independently of'th'eother.

While the term slack ordinarily connotes a cable system, it intended herein -also to comprehend 10st motion of the type available for the same purpose in a stiff link mechanical systern. It also is to be observed that the invention is disc-:l'o'set1 in relation to the synchronization of a pair of machine guns but is applicable to coordination at more than a pair.

From theforegoin'g principles upon which the invention is predicated, and from the following detailed description of the drawings "in which a preferred embodiment of the apparatus is disclosed, those skilled in th'e'art readil will comprehend the various modifications to which the invention is susceptible.

In the drawings:

Figure l is a perspective view showing a pair of machine guns equipped with the synchronizmg fire control or the present invention.

Figure 2 is an elevation looking at the gun side or the primary controller which is adapted to be mounted upon the left hand gun shown in Figure '1.

Figure 311's across sectional View taken on the line 3-3 of Fi ure? Figure 4 is a Vertical cross sectional Vie: through a primary controller adapted to be mounted on the right hand gun of Figure l, the view being taken at a position denoted by line 4+ oiFi'gure 2'.

Figure "5 is a view similar to Figure l taken at a positron denoteu'bythe line "5-5 of Figure 2.

Figure 6 is a view looking up as taken on the line -6 of Figure 2.

Figure '7 is a view taken on the line 'l-l of Figure 3.

Figure 8 is a fragmentary elevational View looking at the outside of the forward portion of the primary controller for the left hand gun of Figure 1, the cover plate being removed therefrom.

Figure 9 is a view of the entire system with the cover plates removed from the primary controllers of both guns and from the intercontrol apparatus, showing the position of all of the parts just before the guns are being fired in unison.

Figure is a view similar to Figure 9 showing the position of the parts just after the guns have been fired.

Figure 11 is a view similar to the Figures 9 and 10 showing relative positions of the parts when one gun is ready to be fired before the other. According to this view the slack has been taken from the system for the left hand gun and is just about to be taken from the system for the right hand gun.

Figure 12 is a fragmentary sectional view showing the means for locking the lost motion device against movement in the event one gun jams.

In the drawings the primary controllers are indicated generally at I; the firing controllers are indicated generally at 2 and the intercontrol is indicated generally at 3. It will be understood that there is one primary controller and one firing controller for each gun to be synchronized and only one intercontroller 3 which is common to them. The guns, as shown in Figure 1, may be of conventional type having bolts 4 respectively extending through elongated slots in the side walls 5 thereof and having sears 6 likewise extending from the side walls. The bolts at their outer extremities carry rotatable rollers 7 thereon, and the primary controllers I are mounted upon the gun side walls so as to derive their operation from the movement of the bolts.

Primary controllers Inasmuch as the primary controllers of the respective right and left hand gun-s are identical, the structure of only one is described. It comprises an elongated casing 8 which is surfaced at its inner face for attachmentto theside wall 5 of the gun by means of screws 9. The outer or opposite face of the casing 8 carries a cover plate I ll which is fastened by screws I I. The casing is divided longitudinally by a vertical mounting wall I2 into a bolt compartment I3 within which the gun bolt roller 1 is operable, and a control linkage compartment I4 at the opposite side of the wall. The rearward portion of each casing carries a solenoid assembly I5 mounted thereon through screws I6. Each solenoid assembly includes a metal housing having a solenoid coil ll therein surrounding a magnetic armature I8 which is actuated when the solenoid is energized. Threaded bosses I9 extend from the casings for receiving appropriate electrical connections to the coils. The function of these solenoids is de-- scribed at a later point in the specification At the gun side of each primary controller, within the chamber I3 thereof, a bell crank ill is rockable upon a stud 2|. One arm of the bell crank extend-s vertically for engagement with the bolt roller 1 as the roller approaches the forward end of its stroke. The bell crank is biased against the movement imparted to it by the roller 1 through a compression spring 22 which is housed in a recess at the forward end of the magazine and the other arm of the bell crank terminates in a rounded face 23 which engages one end of a rocker bar 24 having its pivot, 25, supported in the dividing wall I2 of the controller casing. Tilting movement of the rocker bar actuates one extremity 26 of a lever 21 and a compression spring 28, bearing on a tailpiece 29 of the lever maintains the extremity 26 in contact with the rocker bar. The lever Zl is fixed upon a stub shaft 30 which is journalled in a widened portion of the vertical dividing wall I 2 and which extends therethrough into the linkage cavity I4 of the housing (Figure 4), where it carries a latch lug 3| having a latching shoulder 32 at its forward extremity. Adjacent this shoulder is a seat 33.

At the upper portion of the cavity I3, on the gun side of the primary controller casing, a lever 35 (Figure 2) is mounted upon a cross shaft 35. This lever reaches forwardly and its lower frontwise edge is fashioned as a cam residing in the path of movement of bolt roller 1, whereby the lever is swung upwardly during rearward movement of the roller which occurs directly after the gun is fired. A compression spring 36 having one end seated in a recess at the upper part of the casing and the other end carried in a bore in the lever 34 biases the lever in a downward position into the roller path. Shaft 35, rotatably suported in a widened portion of the vertical wall I2, extends intothe linkage cavity I4 where an arm 33 is fixed to it. A pin 40, projecting laterally from the lower extremity of arm 39 passes irough a resetting link 4| having its forward end connected, through a pin 42, to a supporting lever 53 Which is hung on a stud 45. At a point on the supporting lever lying beyond the connection pin 42, it is straddled by a clevis 46, which in linked thereto by a pin 41. Intermediate the pins ti) and 42 of the resetting link 4| it is associated, through a pin 48, to a link 49 having its upward end assembled to the armature I8 of the solenoid I5.

Pin so, of the drive lever 39, traverses the resetting link 4| through an L-shaped slot. One portion 58 of this slot, extending in a horizontal direction, is a clearance space for the pin which permits the lever 39 to be swung without imparting any movement to the resetting link. The other, vertical, part of the slot lies directly underneath the pin whereby a driving connection between the pin and the resetting link is effected when the link 4| is lifted upon energization of solenoid I5.

A guide block 5| is placed adjacent the linkage cavity I4 to slidably receive a plunger 52 (Figure 3) having its rear end slotted for straddling connection with the forward portion of the clevis attached to the bottom of the supporting lever 43. This clevis presents a latching surface 53 which, when the plunger 52 is moved forwardly, engages the latching shoulder 32 of the lever 3|,

The plunger 52 is bored and threaded to receive the shank of a connector rod 54 which extends therethrough into the plunger 52. (This is shown best in Figure 3.) The plunger is biased in a rearward direction by a compression spring 55 which, housed in a counterbore in the plunger, surrounds the shank of the connector rod 54, its one end abutting the end of the counterbore and its opposite end abutting the end of the bore in the guide block. The connector rod extends beyond the forward end of the guide blo'ck where it is "equipped with a socket for receiving a head or knob 56 of a cable 51 led into the primary :controller from the intercontrol unit 3. The cable preferably is of the metal-shielded type, the shielding :58 within which the cables are slidable being connected to the casings through nuts 59.

Bores so in the casing of the primary controller, through which it is fastened to the wall of the gun barrel by means of the screws 9, all are elongated so as to permit the casing to be shifted longitudinally for cable adjustment purposes.

Briefly, from the foregoing description, it will be seen that as the bolt roller 1 :moves forwardly, it tips the bell crank 26 and, through movement of the rocker 2e, tilts the lever 21 which drives the latch 3| in a downward direction thereby tin-latching the plunger 52. Under the influence of the compression spring 55 the plunger moves rearwardly, tugging upon the cable 51 The result of this action is subsequently described.

Conversely, when the gun is Ifired, bolt roller 1 1 moves rearwardly under recoil to engage cam surface 61 of the lever ssiand lift it. This movement is manifest at the other side of the casing as a forward swinging movement of the resettim link til whereby, "through swinging movement of l the support arm 43, the plunger 52 is thrown forwardly (i. e. presuming that the solenoid has lifted the resetting rod for direct connection). When the plunger 52 is driven forwardly a distance suficient for the latching edge 53 to clear latching shoulder 32 the latch '31 swings upwardly, under the influence of spring 23, to arrest its return. Thus, this operation slack'ens the cable 5:! and latches the plunger in a slack cable position.

Fire control The fire control assemblies 2-2, one for each gun, for actuating the scars thereof 'and to discharge the guns, are mounted upon the gun side Walls 5 5 by means of the bolts 63.

Each 'unit consists of a block having a dovetail 56 extending transversely thereof for rece tion in a dovetail groove which is located in a supportin plate 65. Attachmentbolts 53 have chainfcr heads 56 thereon which engage the opposite edges of the dovetail groove in the supporting plate '55; this arrangement permits the assembly to be shifted for proper positioning over the sear B.

The fire control block 6! for each gun is bored longitudinally to receive a plunger 68, and it also has a threaded nose for receiving a retaining cap as which holds the shield of the fire control cable is, extending thereto from the intercontrol'unit 3. 7

Cable it extends longitudinally through a suitable bore in the plunger '68 and projects beyond the other "end where it carries ahead il. This head bears upon a pivoted clevis "I2 which is pinned as at T3 to an "adjustment stud M threaded into the rearward endwise portion of the plunger '68. A1001; nut '15, hearing against the end of the plunger, maintains the adjustment stud in its set position. Cl'evi's T2 is split as at is to clear the cable "is whereby the cable may be disassembled by 'turningstud 14 to clear the cable head. For this same purpose, the "bore in the adjustment plunger it "issulnciently'large in diameter to pass the heard of the cable.

The forward end of plunger 58 is oounterb'ore'd as at ll to form a recess for a compressionspring 18 which biases the plunger in .a rearward direction. A flat portion 19 on the plunger, engaged by a pin -89 having a mating fiat surface, holds the plunger against rotation.

Intermediate its length the plunger 68 is configurated to provide a cam surface M which bears upon a similar cam surface 82 of a scar actuator 83. The latterpart extends transversely of the fire control assembly through a cavity 84 and its outer face comprises an abutment for engaging the sear 6 to force it inwardly and thereby fire the gun.

In the preferred structure, though not necessarily, the sear actuator has an inward and an outward sliding action and also is pivotal about a fulcrum pin 85 which is at the far side of the cam surface of the actuator at the inward end thereof. The wall of the cavity within which the actuator operates extends outwardly on an angle from the fulcrum 85 to permit the actuator to be tilted and thereby assume a position as shown in Figure 10. A compression spring 83 having one end bearing against a shoulder 8'? on the actuator and the opposite end supported by the casing 6? serves the double purpose in this arrangement of urging the actuator inwardly and also righting it. The actuator, once tilted, rights itself under the influence of the spring when the plunger 68 is moved in a rearward direction such that the cam surface of the actuator is released by and slides upon the cam surface of the plunger 68.

In the operation of this firing assembly a tug upon the cable it pulls the plunger 68 in a forward direction through the action of the cam incline drives the actuator 83 in a transverse direction, causing it to push upon the sear and discharge the gun. Conversely, when the tug upon the cable is released plunger $8 is returned and the actuator 83 moves inwardly.

I nterco'ntrol The intercontrol assembly 3 is a system of coordinated levers, one set for each gun, responsive to the primary control cables 57, and one set interconnected with the firing cables is. These sets of levers are coordinated for the purpose of firing the guns in unison and synchronisin through a floating connection which is cated generally at as, providing lost motion which is available to one less than the total number of guns serviced, e. g., the system shown, the 10st motion is available "to one gun but not to both. When one gun has been conditioned to fire and has utilized the slack which is available from this floating mount then the release of plunger 52 of the other gun, as controlled by the gun bolt thereof, tugs the entire cable system of both guns and they are discharged at exactly the same moment. In this manner each of the guns in effect constitutes a fire control for the system.

The levers of the intercontrol 3 which is illustrated in the drawings are housed within a casing 9| having shield connection nuts 92-92 through which the primary control cables 5'! extend, and having shield connection nuts Ga-E3 for passing the fire control cables Hi-I0. Housing 9! is closed by a cover plate 9% which is fastened in place through screws 95. The floatin'g connection 9%] is located intermediate the side walls of the casing and comprises a stud ilt which has its endwise portions residing in aligned 'slots 97, one located in the bottom wall of the casing and the other in the cover plate. A bore 98 in the interconnecting stud 95 is accessible through a bore 99 in the cover plate.

The primary control cables 57 extend into the cavity within the housing 9i where they are connected to links ISb, one for each cable. The forward end of each of these links I It straddles one arm of a bell crank it! to which it is pinned as at N22. The bell cranks are pivoted upon studs I03 extending upwardly from the bottom of the casing and face one another, with arms thereof projecting beyond the pins I632 to pivotally carry links I56. These links are mounted to the opposite ends of an intercontrol link 5% which is fixed upon the floating stud 9E. The other ends of the bell cranks li'ii carry pins Ibb which respectively traverse slots is? of a cross bar I438. The cross bar has two drag links Iilfi associated therewith, one on the top and one on the bottom, Which are pivotally connected to the cross bar through a pin Iii These drag links respectively operate bell cranks iii, one for each gun, the drag links being pinned to the arms H2 of the bell cranks through pin H3. The respective opposite arms till of the bell cranks i I I extend forwardly where they carry connector links 5 i 5 to which the heads i I 8 of the fire control cable Ill respectively are attached. Bell cranks Hit and Ill rest upon bosses I i? which are appropriately strengthened through ribs and bosses H8 and H9.

The connections of the heads of the cables to the links 563 and H5 may be made in the usual way and the details therefore are not described. It is to be noticed, however, that the connectors for attaching the cables 51 to the plungers 52 in the primary controllers are split units, the halves being drawn together by means of screws I 20, the purpose of this arrangement being to provide connectors having back faces of substantial area which abut the forward ends of the guide blocks 5! when the plungers 52 spring backwardly upon release thereof. This split arrangement also enables some adjustment to be made in the cable.

Method of operation The machine guns have the'usual triggers, not shown, which may be subject to release by the operator through a button controller arranged to accommodate both guns.

Presuming that the guns are loaded, ready for discharge, the actuation of the trigger control causes both guns to be discharged in unison whereupon the bolt rollers l thereof, under recoil, move rearwardly. In the absence of a synchronizing system each gun will continue to operate and fire automatically regardless of the other, so long as the trigger is held. Inasmuch as it is virtually impossible to build machine guns so identical in operation that they will continue to fire in unison, it will be seen that as the guns operate they will fire at different times, first one, then the other. It is this alternate discharging of the guns which imposes a vibratory action on the turret whereby aim is impaired.

In the operation of the present synchronizing apparatus which controls the guns such that they continue to fire in unison throughout their operation, the solenoids l5, energized automatically in any suitable manner, for instance in conjunction with the electric trigger system, serve to dispose the resetting links ll in operative position.

. When the guns fire the bolt rollers 1 are thrown rearwardly into engagement with the cam surfaces 6l of levers 34. The movement of these levers'at eachprimary controller oauseslevers 39 to be swung forwardly whereby the resetting links 4| are driven to thrust the plungers 52 in a forward direction and thereby slacken cables 57. As this occurs the latching levers 3| are free to raise and, by the time the rollers I have left the cam surfaces 6|, the latches 32 have engaged the rear portions of the plungers 52 with the seats 33 of the latches engaging the bottom surfaces of the clevises 46 tolimit upward movement of the latching levers. This operation arrests return movement of each plunger.

The slack in the cables 10 is taken up by the compression springs I8 of the firing controllers. Thus, the springs 78 draw the cable 10 into the firing controls, the opposite ends of the cables during this movement pulling upon thev arms of the bell cranks III to. which they are connected through links H6. Inasmuch as the bell cranks are interconnected at the pin H3 the pin H0 is moved to actuate the cross link I08 and the bell cranks IUI, whereby the latter swing inwardly to take up the slack in cables 57. If these movements in both guns occur simultaneously then the stud 96 of the floating connection remains unaltered in its centralized position.

Figure 9 shows the position of the parts just prior to firing. The rollers I are approaching the forward end of their stroke and further forward movement of either roller will tilt its bell crank 2; this movement will tilt the rocker bar 24' and thereby throw latching lever 3| downwardly to release plunger 52 associated therewith. Therefore, if and when both plungers 52 are released simultaneously the tension springs 55 of the primary controllers drive these plungers backwardly, thereby tugging simultaneously on each cable 51. 7 As the cables 51 are actuated the links I00 move outwardly in unison; bell cranks IIJI are drawn rearwardly and they pull, in unison, upon the interconnecting link I08, whereby, through the links I09, the pin H3 of the bell cranks III cause them also to move in unison, and the movement is transferred simultaneously to both cables 10. These cables, therefore, pull the plunger 68 of the firing controllers in a forward direction and thrust the sear actuators transversely, driving the gun sears 6 inwardly to fire both guns at the same moment. Such a condition is illustrated in Figure 10.

Now, however, suppose that one gun fires at a rate slower than the other. In such an instance the bolt of the faster firing gun reaches releasing bell crank 28 before the other. For instance, the roller 1 at the top part of the drawing in Figure 11 has already actuated its bell crank and the plunger 52 associated therewith already has been released, While the roller I in the primary controller at the bottom of the drawing is illustrated in a position just prior to operating engagement with its bell crank, and the plunger 52 in the lower controller has not yet been released. Under this circumstance the upper cable 57 has been drawn while the lower cable 51 still remains in a slackened condition.

The tug upon the upper cable 51 is absorbed at the intercontrol unit 3 through a shift in the position of stud 96. Thus, as the upper cable 5'! moves in the direction of the arrow, the link I0 is pulled outwardly and link I04 is actuated.

At the other side of the system cable 51 is in slack condition, but the bell crank l0l is not free to move because cable I0 is under the infiuenceoi compressionspring I8 and this cable 9 holds the hell crank H t relatively against movement. Therefore these difierential forces upon the respective cables and associated bell cranks. cause link N34 to pivot the lever Hi about stud 96' and at the same time shift stud 96 from its centralized position. At the same tim the movement, of the upper bell crank Hll causes the cross connecting link M8 to be canted to an angular position. These movements of the, parts have absorbed the tug which was placed upon the cable system when. the. plunger 52 of. the upper firing control was released and, therefore, have prevented; the upper firing controller from being actuated. Moreover, the entire cable system is now placed in condition, to transmit motion.

Next, when the bolt roller 1 of the lower fire controller in Figure 11. tips its bell crank 28 and thereby releases its plunger 5'2, its cable :3? will tug upon the lower bell crank I'll. This movement of the lower bell crank. Nil drives the lower end of the connecting link 1,08 thereby pulling upon the pin I [3 which actuates both. bell cranks Hi in unison and thereby pulls upon both ring control cables ill to discharge the guns at the same. moment, At this time floating stud 5 recentralized. and the parts reassume the position shown, in. Figure 1.0.

The bore, 98 in. the floating stud 95 and the aligned bore 99 in the cover plate 34 of the inercontrol. unit. are Int nded. for reception of a pin 52!, actuated either by hand. or, selectively, y a s lenoid. Electrical; means for operatin the pin. to decommission. the lost motion device. is shown in detail in co-pending patent application 6015M filed Junev 25., 1&45. Insertion of a pin I2! locks the stud 96 against floating movement and such an. operation individualizes the controls of the two guns whereby either may be operated by the other, i. e.,, upon insertion of the pin, release of plunger 52 of either control actuates its cable 5! and pulls upon the firing cable iii. If one of the guns is jammed the operation of the other is still preserved.

Deenergization of the solenoids 1 p mits the Dlungers thereof to drop and. this i ns the horizontal slots 5i] in the.- resetti-ng links with the drive pins 40 therefor, whereby levers 3.8 may be shifted without causing the plungers to be reset. Conversely, if desirable, the solenoids may be wired and arranged to actuate the resetting links to their inoperative position when the solenoids are energized and allow the resetting links to move to connected positions when the solenoids are deenergized, or the solenoids may be provided with compound coils for positively moving the plungers in either direction.

The electrical control of the organization is fully shown and described in my copending application Serial No. 601,504.

Having described my invention, I claim:

1. Mechanism for synchronizing the discharge of a pair of machine guns having gun bolts sears, comprising cables for actuating the respective gun sears, means controlled by the bolts of the guns for tugging on the cables to actuate the scars, and a floating connection between the cables for absorbing the tug exerted upon the cable of one gun when it is conditioned to fire, but not both, whereby the tug exerted upon the other cable by the other gun causes both cables to be tugged simultaneously through the floating connection to fire the guns simultaneously.

2. Mechanism for synchronizing the discharge of multiple machine guns having sears, said mechanism comprising; primary controllers, one for each gun, each primary controller hav ng a connector extending therefrom, each primary controller comprising means for biasing said. c nnector in one direction and. latching means for holding said connector against said biasing means, firing controller's, on for each gun, for actuating the sears thereof, and a linkage system including a floating member which is common to the connectors from the primary controllers and which is also in connection with thev firing controllers, the said floating member being subject to limited lost motion. movement responsive to the firing of one gun before another thereby renderin the linkage system ineffective for transmitting control movements. from that primary controller to its firing controller until the other gun is ready to be fired, the amount of Said lost motion movement being so limited that the linkage system is thereafter rendered. effective for transmitting control. movements from the primary controller of the gun, last ready to be fired.

3. A synchronizing system for machine guns each having a bolt and a. scar, said system including a primary controller having a translating member biased inv one direction, a latch for holding the translating member in its biased position, means responsive. to the bolt. 0f the gun for tripping said latch and permitting said translating member to move und r the influence of said biasing means, a member responsive to the movement of the gun bolt at another position thereof for relatchin said translating member, a mechanical linkage actuated by said translating member, a firing controller ncluding a member positioned for engagement with the gun scar and actuated to fire the gun in response to movement of said mechanical. linkage, and. an intercontrol device in connection with said mechanical linkage, said interoontrol device including a floating connection for limiting the amount of motion capable of being transmitted through said mechanical linkage in, response to coordinate control of another primary controller of another machine gun.

4. An armament system. comprising a pair of ine guns, each having a primary controller thereon, an interoontrol unit, and firing controllers, one for each gun, mechanical linkages extending from the respective primary controllers to the interoontrol unit and from the interoontrol unit to the respective firing controls, the primary controllers being effective for actuating the intercontrol unit through the mechanical linkages in response to gun operation, and the intercontroller being effective to actuate the firing controllers through the mechanical linkages and thereby discharge the guns in response to actuation of the interoontrol, said interoontrol having a lost motion device therein which is common to the mechanical linkages for limiting the transmission of motion from one primary controller to the firing controller of the same gun until the primary controller of the other gun is actuated.

5. An armament system comprising a pair of machine guns, each having a primary controller thereon, an interoontrol unit, and firing controllers, one for each gun, motion transmitting linkages extending from the respective primary controllers to the interoontrol and from the interoontrol to the respective firing controls, the primary controllers being effective for motivat ing the interoontrol unit through said linkages in response to gun operation and the intercontroller being effective to actuate the firing controllers through said linkages and thereby discharge the guns in response to motivation of the intercontrol, 'said intercontrol having a lost motion device therein which is common to the linkages, for limiting the transmission of motion from one primary controller to the firing controller of the same gun through said linkages until the primary controller of the other gun is actuated, and means for rendering the lost motion device of the intercontrol unit ineffective, whereby the primary controller of either gun is effective for actuating the firing controller thereof.

6. An armament system comprising a pair of machine guns, each having a primary controller thereon, an intercontrol unit, and firing controllers, one for each gun, mechanical linkages extending from the respective primary controllers to the intercontrol and from the intercontrol to the respective firing controllers for actuating the intercontrol unit through. said linkages in response to gun operation and for actuating the firing controllers through said linkages to discharge the guns in response to actuation of the intercontrol, motion device therein which is common to the mechanical linkages for limiting the transmission of motion from one primary controller to the firing controller of the same gun until the primary controller of the other gun is actuated, and means for rendering the lost motion device of the intercontrol unit ineffective, whereby the primary controller of either gun is effective for actuating the firing controller thereof independent of the firing controller of the other gun,

said intercontrol having a lost said intercontrol device having a lost motion element which is effective for limiting the amount of movement capable of being transmitted through said linkages from the primary controllers to the firing controllers, the amount of lost motion being such that it is taken up in response to the actuation of a primary controller of one gun and the linkages are thereby rendered effective for transmitting motion from the primary controller of the other gun to the firing controllers of both guns.

8. Mechanism for effecting the firing of two guns simultaneously, comprising; a primary controller for each gun which is responsive to the operation of that gun, a firing controller for each gun adapted to be actuated to cause the firing of that gun, a linkage interconnecting th primary controller of each gun with the fire controlling thereof, an intercontrol device connected in common to said linkages whereby movement of one linkage may be transmitted to the other, the said intercontrol device having a lost motion element which is effective for limiting the amount of movement capable of being transmitted to the other, the said intercontrol device having a lost motion element, which is eiiective for limiting the amount of movement capable of being transmitted through said linkages from the primary controllers to the firing controllers, the amount of lostmotion beingsuch that it is taken up in response to the actuation of a primary controller of one gun and the linkages are thereby rendered effective for transmitting motion from the pri mary controller of the other gun to the firing controllers of both guns; and means for rendering said motion device ineifective for providing lost motion.

VICTOR F. ZAHODIAKIN.

REFERENCES CITED The folloiwing references are of record in the file of this patent:

I UNITED STATES PATENTS Number 

